In December 2011 people who attended a holiday party on December 3 or a wedding reception on the same day at an event center in Duluth, Minnesota became ill with norovirus. Staff from the Minnesota Department of Health (MDH) interviewed 71 wedding guests and 12 holiday party guests. Sixty-two guests met the case definition including 50 wedding guests and all 12 holiday party guests interviewed. Two patron stool specimens were positive for norovirus GII.

Food for both events featured butler-passed hors d’oeuvres and a buffet dinner. The two events had different menus, but food for both was prepared in the same kitchen. No individual food items served at the events were found to be significantly associated with illness.

Interviews with employees revealed that 8 staff reported recent gastrointestinal illness, with onset dates from November 25 to December 11. One employee reported working December 3 while actively having vomiting and diarrhea. Five employees tested positive for norovirus GII, including the food worker who worked while ill on December 3.

Investigators concluded that the source of contamination was one or more ill foodhandlers who had contact with ready-to-eat foods served at the events.